Simple script to resize object
If all you want to set for the operator is a single property, you can do:

col.operator("transform.resize").value = (2,2,2)


If you want to set multiple properties, use the object that is returned by .operator() and set the properties on it one after another:

props = col.operator("transform.resize")
props.value = (2,2,2)
props.constraint_orientation = 'GLOBAL'